On Monday we posted an explainer about HDMI's CEC protocol, which uses a small wire inside HDMI cables to carry command signals between HDMI devices. Ideally, this makes expensive all-in-one remotes unnecessary, since your TV can relay commands to other connected devices. In reality, there are some limitations--proprietary command protocols can prevent inter-brand communications, for example.
Pulse-Eight, the company behind that XBMC remote we looked at a few months back, has turned its attention to HDMI consumer electronics control with a USB adapter that will bring CEC functionality to home theater PCs. The adapter, available for pre-order on the Pulse-Eight store, will tie into XBMC and allow you to control your TV and media center through a single remote.
CEC support is planned for the next release of XBMC and the group hopes to add support into the current stable release as well. Once XBMC support is locked in, Pulse-Eight will move on to getting the adapter up and running with Windows Media Center. Pulse-Eight also notes that cross-brand communication should be possible using PC software, as well. If your custom built HTPC and Panasonic TV and Sony amp all support CEC, the CEC Adapter should allow all of them to talk to each other and relay commands from a single remote.
The CEC adapter ships on September 26 for $47.98.